Hydrocarbon oil conversion process



NOV 27, 1956 c. E. HEMMINGER HYDROCARBON OIL. CONVERSION PROCESS FiledJune 3o, 1954 V mm www

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Charles E. Hemmlnger 'Inventor By Attorney United States Patent O"2,772,215 HYDROCARBON OIL CQNVERSON PROCESS Charles E. Hemminger,Westfield, N. J., assigor to Esso Research and Engineering Company, acorporation of Delaware Application rune 30, 1954, serial Na. 440,389 eClaims. (ci. 19e- 49) This invention relates to the art of convertinghydrocarbon oils. It is concerned with a method for upgrading heavypetroleum oils in the nature of vacuum residua and for producing a highquality product suitable for use as a motor fuel. In its more specidcaspects, the present invention reforms naphthas to obtain gasolines ofhigh octane ratings while concurrently upgrading residual oils byhydrogenolysis. The present invention proposes to utilize the hydrogenand the highly aromatic polymer produced by hydroforming operations totransform low value residua into middle distillates.

It is known by the art to upgrade hydrogen-decient oils such as vacuumresidua, tars, asphalts, etc. to more valuable liquid distillates bythermally treating the hydrogen-deficient material in admixture with ahydrogen donor diluent material. The donor diluent is a material,aromatic-naphthenic in nature, that has the ability to take up hydrogenin a hydrogenation zone and readily release it to a hydrogen-decient oilin a thermal cracking zone. The hydrogen donor diluent is speciallyprepared by partially hydrogenating, by conventional means, a selectedpetroleum oil fraction that is predominantly composed ofaromatic-naphthenic constituents having hydrogen transferringcharacteristics. In this manner of hydrocracking of oils, the oil beingupgraded is not contacted directly with hydrogenation catalyst and doesnot, therefore, impair its activity by contamination. The amount ofconcomitant light gases and coke produced by this hydrogen donor diluentcracking (HDDC) process is relatively small, usually being in the orderof about to 10% The prior art has suggested, for example, that a thermaltar boiling in the range of about 700 to 900 F obtained by the thermalcracking of catalytic cycle oils will serve admirably as a hydrogendonor diluent. Such a material contains condensed ring aromatics insufficient quantities to economically serve as a hydrogen carrier. Thematerial is partially hydrogenated such that there is added to it someeasily removable hydrogen atoms but not enough to convert the aromaticsin the material substantially to naphthenes. This material, after beingpartially hydrogenated, is admixed with an oil such as a vacuum residuumand the mixture is thermally treated, whereby the hydrogen istransferred from the partially hydrogenated material to the residuum,thereby upgrading the residuum. It is believed that the donor diluentoperates by yielding hydrogen atoms to the radicals that have beencreated from the residuum by the thermal treatment, thereby preventingcondensation and/ or polymerization of the radicals.

In normal HDDC operations, as the donor diluent material issubstantially unaltered as it passes through the process, it iscustomary to recycle the material so that it is used over and over againas a hydrogen carrier. Losses of about 2 to 20% of the diluent materialhave been encountered due, perhaps, to some cracking of the diluent andto imperfect separation techniques.

Vlt has now been discovered that the polymer produced by catalyticnaphtha-reforming operations contains a type of compound suitable foruse as a hydrogen donor or carrier and in quantities sufficient to beeconomically attractive. Also, it has been found that the light gasesproduced during the hydroforming operations contain a suiciently .leumderived oils.

2,772,215 Patented Nov. 27, .1956

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high percentage of hydrogen to serve to partially hydrogenate thepolymer material in a'hydrogenation zone.

It is an object of the present invention to use materials from catalyticnaphtha-reforming operations, normally surplusage in a renery, as ameans to upgrade high boiling, low value oils to more economicallydesired distillates, e. g., gas oils suitable for catalytic cracking andnaphthas suitable for hydroforming. Because of the diluent losspreviously mentioned, the integration of the two types of hydrocarbonoil conversion processes, e. g residuum upgrading and naphtha reforming,isaccomplished by maintaining select optimum boiling range division ofthe-products, recycle rates, treating temperatures, etc.

As is known by the art, hydroforming processeslnormally have a highyield of reformed product based upon feed with only a smallpercentage,say 1 or 2%, of the naphtha feed being degraded to heaviermateriahe.Lg.,

polymer, by condensation and polymerization reactions.

By maintaining optimum conditions, however, the present invention isable to maintain a sudicient quantity of donor diluent in the residuumupgrading or HDDC step of the process of this invention by use ofthepolymer with, perhaps, some of the heating oil produced during the HDDCstep.

To produce a heavy polymer in the hydroforming step, to serve as adonor, a wider cut of naphtha from HDDC step is cycled and fed to thehydroformer than is usual-in hydroforming. For example, 350 F. is theusual endpoint for virgin feeds but in the present invention a 450 to550 F. endpoint thermal naphtha is fed to the hydroformer. The 375 plusmaterial is the source of heavy recycle polymer as diluent for HDDC. TheYoctane number of the thermal naphtha is improved bythe hydroformingfrom about 60 to 90. Research O. N., sulphur is removed and the gasolineis stabilized.

Thus a primary object of the present invention is to convert and upgradehydrocarbon oils, particularly petro- Another object is to upgradeselected oil fractions, particularly heavy naphthas and residual oilfractions, to liquid distillates of improved quality. Still another,more particular, object is to devise a process whereby low octanenaphthas are reformed'to yield high octane products and whereby hydrogendecient oils are upgraded to light and middle distillates. The hydrogendeficient oils that may be treated by the process of this inventioninclude coal tars, shale oils, extracts, tars,

,asphalts, cycle stocks, whole crudes, distillate and residual fractionstherefrom, or mixtures thereof. p

These and other objects and advantages will more clearly appear as theattached drawing, forming a part of this specication, is described indetail. The drawing schematically portrays one preferred embodimentofthe invention, designed to attain its objects.

Generally the objects of this invention are met by passing a virginheavy naphtha and a heavy thermal naphtha through a catalytic reformingzone, preferably a fluid bed hydroforming zone with regenerationfacilities containing a molybdenum oxide catalyst. The eilluent from thereforming zone is separated to obtain -a hydrogen-rich gas, high octanenaphthas and a somewhat higher boiling hydrocarbon stream rich inaromaticnaphthenic constituents, e. g., polymer. The hydrogen rich gasis used to partially hydrogenate the polymer in a conventionalhydrogenation zone. This hydrogenation zone in a preferred embodiment ofthis invention uses as the hydrogenation catalyst the same catalyst usedfor the reforming operation, e. g., molybdenum oxide, and thehydrogenation is affected by operating at somewhat lower temperatures.The resulting partially hydrogenated liquid product, e. g., hydrogendonor diluent, is admixed with a hydrogen-deicient oil and subjected tothermal treating whereby the donor diluent gives up activation.

hydrogen tothe hydrogen-deficient oil while the hy-V drogen-deficientoil is being thermally cracked. The thermally treated mixture is thenseparated to obtain: a residual fraction, a portion` of which can berecycled for further thermal treating; a Vgas oil fraction boiling intherange of about 600 to 1015 F., suitable as feed for catalyticcracking; a heating oil fraction, a portion of vwhich may behydrogenated Yto save as hydrogen donor diluent; a heavy naphthafraction boiling in the range of about 200 'to 550 F. which istransferred to the hydrof former to be treated therein; and a lightnaphtha fraction boiling in the range of about C4 to 200 F. which is ofsuitable quanity for direct marketing with very little furthertreatment.

l The feed streams tothe process of this invention may be derived fromany convenient source. Advantageously both streams ycan be obtained fromthe initial separation of a whole crude.l Thus the hydrogen-deficientmaterial can be the vacuum bottoms from the primary fractionation of thecrude and the material for reforming can be the virgin heavy naphthaboiling in the range of about mands of the process.

There are known in the art several catalytic reforming processes such asfixed and fluid bed processes, re-

Ypromotes catalyst life. Y Broadly, any hydroforming process is suitablefor use with the process of this invention. Preferably, however, a uidbed hydroformer with ya cataiyst regeneration system is used. Alsopreferably, a molybdenum oxide' catalyst supported on alumina inparticulateform is used as a catalyst as this type of catalyst isparticularly resistant to contaminationV and de- Further, this catalystwill serve as a hydrogenation catalyst and if used as such allows thehydrogenation catalyst to be regenerated in a regenerator common to theuid bed hydroformer.

Referring now to the drawing, the major items of equipment shown arehydrogen donor diluent cracking reactor 1 with a fractionation column 2,for the separa- Ation of the materialstreated in the HDDC step, -ahydro- "200-'to 550 F. Virgin naphthais preferred as it will V'generatesufficient quantities of hydrogen to meet the deformer V3 with afractionator column 4, and a hydrogena- Y tion vessel 5 with a separator6.

The process will bel described using a uid bed hydrovformer as anexample, although the catalyst regenerator is not shown. This method ofhydroforming is well known by the art. The operating conditionsapplicable to the process of this invention are conveniently surnmarizedin Table I, presented hereinafter.

The naphthas to` be reformed are introduced into the i hydroformer,after being preheated,.by line 7. The heatcarrying recycle gas issupplied to the hydroformer by line 8. The conditions are selected so asto obtain the desired degree of octane improvement of the naphthas.Effluent from the hydroformer is transferred to ;a separation system vialine 9. Light gases are removed from the hydroformer effluent byseparator 36. The condensed material is then transferred by line 40 tofractionator 4 wherein light hydroformate is separated and removed byline 11. Line 12 removes heavy hydroformate boiling in the range ofabout 250 to 400 F. Line 13 genation vessel by lines 16 and 17. The feedto the hydrogenation vessel may be suitably 'preheated in: heatexchanger 18 as by heat exchange with various streams of the process orwith flue gases, etc.

The hydrogenation vessel may be of a conventional type that will securesucient partial hydrogenation of the polymer material. v For example, afixed bed hydrogenation vessel using a nickel tungsten sulfide catalystas 3/16" pills will give the proper degree of hydrogenation of thediluent when operated at conditions in the range of 650 to 800 F., 200to 1000 p. s. i. g. and 0.2 to 2.0 v./hr./v.

Preferably, however, a iluid bed hydrogenator is used operating with thesame catalyst as the hydroformer, e. g., molybdenum oxide. With thispreferred arrangement, if the hydrogenation catalyst ybecomes fouled, itcan then be regenerated in the hydroformer regenerator.

The hydrogenated donor diluent is transferred by line 19 to a separatorwherein light gases are removed by line 20 and passed to thehydroformer. materia-l is then transferred to the HDDC reactor by line21.

The materials supplied tothe hydroformer are, of course, suitablypreheated to supply the'necessary heat for the reaction. The light gasesare preheated in heat exchanger system 22 which includes heat exchangewith various streams of the process and final heating furnaces that heatthe gas to about 1200 F. The naphtha streams are similarly preheated inheat exchange means 23. Also, in a uid bed hydroforming process, heatwill be obtained through the catalyst from the regeneration system.

The material introduced into the HDDC reactor, including bottomsrecycled by line 24, the hydrogen-decient residua supplied by line 26and the donor diluent supplied by line 21, are also heated in a heatexchange means 25 to maintain the necessary cracking temperature. Eachof these streams can, of course, be separately preheated in such amanner that they will convey the highest quantity of heat possible tothe cracking reactor short of being unduly thermally degraded by hightemperatures.- From the heat exchange means 25, the materials areintroduced into a vsoaking drum 1, wherein they are maintained underconditions of time, temperature andprerssure sucient to attain thedesired degree of conversion and hydrogen transfer. Normally a coil anddrum arrangement will be used for the HDDC reaction. However, in manyapplications, a heating coil or furvnace Yalone will be suicient tocarry out the reaction.

The cracked materials are then transferred by line 27 to fractionator 2.Light gases are separated and removed from the fractionator by line 28and a light naphtha fraction boiling in the range of about Ca to 200 F.is removed by line 29 as product. Line 30 conveys to the hydroformer aheavy thermal naphtha fraction boiling in the range of about 200 to 550F. that contains a major portion of the spent donor diluent. A heatingoil fraction is removed as product by line 31.- To aid in themaintenance of the diluent balance in the process, a portion of thisheating oil fraction is recycled by line 14 to the hydrogenation zone,although incertain applications it may not be necessary to do this.Y Agas oil boiling up to about 900 to ll00 F. is removed by line 32 and mayadvantageously be catalytically cracked to secure further quantities ofhigh octane gasoline. A major portion of the remaining heavy bottoms aretransferred by line 24 to the HDDC unit for further treatment. Ayportionof these bottoms amounting to about 5 to 25% based on residuafeed are bled from the process by line 33 in ,order to prevent excessivebuild-up of contaminants, ash con-A maticnaphthenic materialshydrogenated to form the hy- TheV hydrogenatedV lj t drogen donordiluent. The cut point will depend primarily on the type of feed andextent of conversion in the HDDC step. The heating oil recycle ratiowill, of course, change in accordance with the change in heavy naphthacut point. Y

The following Table I summarizes the pertinent range of operatingconditions applicable to the process of this invention and presents aspecific example of operating conditions. Table II illustrates theproducts that may be obtained from this process when using the type offeed stocks indicated and operating in accordance with the eX- ample inTable I.

TABLE I Operating Conditions Range Example 15 DC unit coil and drumHDTemperaure, "F 800 to 950 850 Pressure, p. s. i. a. 200 to 1,000 400Throughput, v./hr./v 0. 5 to 10 2.0 Donor diluent/residuuui ratio 0. 1to 3 5 20 1,000 F. minus Conversion,I Vo Percent 40 to 70 60Hydrolorming unit (Fluid hydroiormer with continuous regeneration):

Catalyst (2) Temperature, F 850 to 975 900 Pressure, p. s. i. a 100 to500 215 26 Catalyst/oil 0.2 to 2.0 0.8 Throughput, v.lhr lv 0. 3 to 1. 50. 8 Research Octane of C 80 to 98 00 Hydogenation unit (Fluid Bed): (z)

Temperature, "F 650 to 800 720 Pressure, p. s. i. a. 175 to 500 215Throughput. v/hrJv 0.2 to 2.0 0. 5 30 Hz consumed, S. C. Fjbbl. d nent300 to 2,000 S Diluent boiling range, F 400 to 750 400-550 l Of totalfeed to unit including donor diluent; 1000 F. plus conversion en uals100 vol. percent feed minus vol. percent of products boiling above 1000F Sulfur, wt. percent.

Net Products, percent based on total fresh feed, equal volumes ofresidua and naphtha:

Ca and lighter gases (51% H2) .Wt. percent 7 (li-200 l?. light naphtha(70 octane) (li-350 F. light hydroforinate (90 octane) 350-430 F. heavyhydroformate (100 octane) 450-650 F. heating oil (40 Diesel Index) vo1.percent..

650-1015o F. gas oil 1015 F.+uel oil. d 15 Coke wt. percent 2 R. V. P.gasoline, with extraneous C@ addition vol. percent-. 73 Internal Flows:i

10157 F.|bottoms to HDDC,/bbl. residua bbl.. 0. 90 Donor Diluent toHDDC/bbl. residua ..hbl 0. 5 200-450 F. thermal naphtha tohydrot'orming/bbl. virgin napllitha 5 H r. 5) bbli1 0.7 Rec ce asl 75 1o oorming virgin nap thy; g y S. C. F 4000 Polymer to hydrogenation/bbl.residnum bbl-- 0.3 Heating oil to hydrogenation/bbl. rcsiduum bbl-- 0. 2Gas (75% Hz) to hydrogenation/bbl. polymer and heating ou S. C. F..20,000

1 Includes gas from hydroformer product and from hydrogenator.

From the preceding description, it can be seen that the presentinvention advantageously utilizes the normally waste materials producedby a hydroforming process to upgrade hydrogen deficient, low value oils.

Having described the invention, what is sought to be protected byLetters Patent is succinctly set forth in the following claims.

What is claimed is:

l. A hydrocarbon oil conversion process which comprises reforming in acatalytic reforming zone a heavy virgin naphtha boiling in a rangewithin the ilmits of 200 to 550 F. in the presence of a reformingcatalyst and free-hydrogen containing gas to obtain a hydrogen rich gas,naphthas of substantially higher octane and a higher boiling hydrocarbonstream rich in aromaticnaphthenes, reheating and returning a portion ofsaid hydrogen rich gas to said catalytic reforming zone as said freehydrogen containing gas, partially hydrogenating at least a portion ofsaid higher boiling hydrocarbon stream using said hydrogen rich gas as asource of hydrogen to obtain a partially hydrogenated hydrogen donordiluent, admixing l volume of residual oil with 1 to 3 volumes of saidhydrogen donor diluent, subjecting the resulting admixture to conditionsof hydrogen donor diluent cracking to obtain lighter products includinga heavy thermal naphtha boiling in a range within the limits of about200 to 550 F., and light gas oils and passing said thermal naphtha tosaid catalytic reforming zone to be reformed therein along with saidvirgin naphthas, the end boiling points of said virgin and thermalnaphthas being adjusted to maintain the proper balance of said hydrogendonor diluent in the process.

2. The process of claim l wherein a portion of said light gas oils arepartially hydrogenated along with said higher boiling hydrocarbonstreams to obtain said hydrogen donor diluent.

3. A process for reforming naphthas and for upgrading hydrogen decientpetroleum oils comprising hydroforming a virgin naphtha boiling in therange of about 200 to 550 F., and a thermal naphtha obtained ashereinafter described in a hydroforming zone containing a fluid bed ofhydroforming catalyst and operating at a temperature in the range of 850to 975 F., at a pressure in the range of to 500 p. s. i. a., and at athroughput in the range of 0.3 to 1.5 v./hr./v. to obtain a hydrogencontaining gas, a light hydroformate, a heavy hydroformate boiling inthe range of about 350 to 430 F., and polymer, circulating saidhydroforming catalyst to a uid bed oxidation-regeneration zone and backto maintain the catalytic activity of said hydroforming catalyst,hydrogenating said polymer in a hydrogenation zone containing ahydrogenation catalyst, using at least a major portion of said hydrogencontaining gas as a source of hydrogen and operating at a temperature inthe range of 650 to 800 F., a pressure in the range of 175 to 500 p. s.i. a., and at a throughput in the range of 0.2 to 2.0 v./hr./v. toobtain a partially hydrogenated donor diluent, admixing said partiallyhydrogenated donor diluent with a heavy petroleum oil in a proportion inthe range of about 0.1 to 3 volumes diluent/volume of oil, thermallytreating the resulting mixture in a thermal treating zone operating at atemperature in the range of about 800 to 950 F., at a pressure in therange of about 200 to 1000 p. s. i. a., and at a throughput in the rangeof about 0.5 to l0 v./hr./v. to obtain light naphthas, a heavy thermalnaphtha boiling in the range of about 200 to 550 F., higher boilingdistillate fractions and residue boiling above a temperature in therange of 900 to ll00 F., and passing said heavy thermal naphtha to saidhydroforming zone to be treated therein.

4. The process of claim 3 wherein said hydrogenation zone contains a uidbed of molybdenum catalyst.

5. The process of claim 3 wherein said heavy petroleum oil includesheavy residual oils boiling above about 900 F.

6. The process of claim 3 wherein at least a portion of said higherboiling distillate fractions is transferred to said hydrogenation zone.

References Cited in the file of this patent UNITED STATES PATENTS2,373,673 Fuller Apr. 17, 1945 2,426,929 Greensfelder Sept. 2, 19472,620,293 Blue et al Dec. 2, 1952

1. A HYDROCARBON OIL CONVERSION PROCESS WHICH COMPRISES REFORMING IN ACATALYTIC REFORMING ZONE A HEAVY VIRGIN NAPHTHA BOILING IN A RANGEWITHIN THE ILMITS OF 200* TO 500* F. IN THE PRESENCE OF A REFORMINGCATALYST AND FREE-HYDROGEN CONTAINING GAS TO OBTAIN A HYDROGEN RICH GAS,NAPHTHAS OF SUBSTANTIALLY HIGHER OCTANE ADN A HIGHER BOILING HYDROCARBONSTREAM RICH IN AROMATICNAPHTHENES, REHEATING AND RETURNING A PORTION OFSAID HYDROGEN RICH GAS TO SAID CATALYTIC REFORMING ZONE AS SAID FREEHYDROGEN CONTAINING GAS, PARTIALLY HYDROGENATING AT LEAST A PORTION OFSAID HIGHER BOILING HYDROCARBON STREAM USING SAID HYDROGEN RICH GAS AS ASOURCE OF HYDROGEN TO OBTAIN A PARTIALLY HYDROGENATED HYDROGEN DONORDILUENT, ADMIXING 1 VOLUME OF RESIDUAL OIL WITH 1 TO 3 VOLUMES OF SAIDHYDROGEN DONOR DILUENT, SUBJECTING THE RESULTING ADMIXTURE TO CONDITIONSOF HYDROGEN DONOR